Locking device for telescopically fitted parts



March 26, 1963 o. s. OWENMARK 3,083,041

LOCKING DEVICE FOR TELESCOPICALLY FITTED PARTS Filed Dec. 31, 19s"? INVENTOR. 0401/ 572/125) au zmwex BY y f; l 4

United States Patent 3,083,041 LOCKING DEVICE FOR TELESCQPICALLY FITIED PARTS Olov Stanley Owenmark, Stockholm, Sweden, assignor to Aktiebolaget Electrolux, Stockholm, Sweden, a corporation of Sweden Filed Dec. 31, 1957, Ser. No. 706,317 Claims priority, application Sweden Jan. 10, 1957 1 Claim. (Cl. 2857) My invention relates to a locking device for telescopically fitted parts.

' It is an object of my invention to provide an improved locking device of this type which is of simplified construction and effectively locks telescopically fitting parts.

Another object of the invention is to provide an improved locking device of this type which can be operated without the use of tools for adjusting at will the overall length of the telescopically fitted parts. I accomplish this by threadedly connecting the telescopically fitting parts with structure having cooperating members, of which one is movable on the telescopically fitted part with which it is associated and resiliently fixed thereto.

Further objects and advantages of my invention will become apparent as the following description proceeds, and the features of novelty which characterize my invention will be pointed out with particularity in the claim annexed to and forming a part of this specification.

For a better understanding of my invention, reference may be had to the following description taken in connection with the accompanying drawing, in which:

FIG. 1 is a perspective view of a suction cleaner having a cleaning appliance connected to an adjustable wand pro vided with a locking device embodying my invention;

FIG. 2 is an enlarged fragmentary perspective view, partly broken away and in section, of the adjustable wand shown in FIG. 1 to illustrate the locking device more clearly; and

- FIG. 3 is an exploded perspective view of the locking device shown in FIG. 2 to illustrate details.

Referring to the drawing, I have shown my invention in connection with a horizontal tank-type suction cleaner which includes a casing having an end cover 11. The end coverfll is provided with an inlet 11a to which a suction hose 12 is adapted to be removably secured in any suitable manner (not shown). Suitable cleaning appliances, such as a nozzle 14, for example, may be connected to a wand 13 which in turn is connected to the outer free end of the hose 12 and through which air is drawn into the casing '10 by a suitable motor-fan unit (not shown) disposed therein. Dust and dirt entrained in the air during a cleaning operation are separated from the air when the latter passes through a dust collecting member (not shown) disposed in the casing, and air from which dust and dirt has been removed is discharged from the casing 10 from the end thereof opposite the end cover 11. p 7 I The adjustablewand 13, which is employed to manipulate the nozzle 14 over a surface to be cleaned, comprises outer and inner tubular members 16 and 17, respectively, which are formed to fit telescopically one within the other. After the tubular members 16 and 17 are moved lengthwise of each other to provide a wand 13 of the desired length, as between the solid and dotted line positions illustrated in FIG. 1, the tubular members 16 and 17 may be clamped to one another by a locking device 15.

In accordance with my invention, the locking device comprises a hollow sleeve-like element 20 in the form of a split ring which is externally threaded and provided with spaced apart lugs or bosses 21 at its inner surface. The element 20, which is resilient in character, is mounted in 3,083,041 Patented Mar. 26, 1963 position on the outer tube 16 by expanding the element sufficiently to enable it to be moved over a conical-shaped end portion 18 of the outer tube to a region at the immediate vicinity of slots or openings 19. In its mounted position on the outer tubular member 16, the openings 19 receive the lugs 21 of the element 20 and the latter assumes its undistorted shape seen in FIG. 3, the element 20 in such mounted position being in juxtaposition to the small end of the conical-shaped portion 18 of the outer tube 16.

The element 20 forms an externally threaded end portion of the outer tube 16, and, due to the inherently resilient character of the element, the lugs or bosses 21 are effectively held in the slots 19 so that the element 20 forms a unitary part of the outer tube 16 and is always movable therewith.

The externally threaded element '20 is adapted to receive an internally threaded hollow member or nut 25 within which is disposed a locking element 22 which also is resilient in character. The hollow member 25, which is formed with an outer serrated surface, is provided with an inturned flange 28 defining an opening 27 through which the locking element 22 is moved when it is mounted on the member 25 to form a unitary part thereof.

One end of the locking element 22 is provided with a pair of spaced apart beads 29 and 23 having a ring-shaped groove therebetween which is adapted to receive the inturned flange 28 of the hollow member 25. The opposite end of the locking element 22 is wedge-shaped, as best seen in FIG. 3. In order to facilitate assembly of the locking element 22 on the hollow member 25 and also provide a locking element which is resilient in character, the element 22 at its beaded end is formed with spaced apart V-shaped notches 23 and at its opposite wedgeshaped end is formed with parallel spaced apart slits 23a to provide a plurality of clamping jaws 22a.

In its undistorted position illustrated in FIG. 3, the inner diameter of the hollow locking element 22 is slightly smaller at its wedge-shaped end 22a than at its beaded end 29. When the locking element 22 is mounted in position on the hollow member 25, the element 22 is inserted into the member 25 by moving it toward the right in 'FIG. 3 and through the open internally threaded end thereof. Since the bead 29 is beveled, the latter readily moves over the inturned flange 28 of the member 25, the resilient sections 24 of the element22 readily yielding until the flange fits in the ring-shaped groove formed between the beads 23 and 29.

Let us assume that the hollow member 25 and locking element 22 illustrated in FIG. 2 are disengaged from the externally threaded element 20, but still mounted as a unitary body on the inner tubular member 17. In such case, the locking element 22 is in frictional contact with the tubular member 17, such frictional contact being greatest at the region of the clamping jaws 22a due to the fact that the inner diameter of the locking element, when the latter is undistorted, is slightly smaller at its wedge-shaped end than at its opposite head end 29.

The frictional contact of the locking element 22 with the tubular member 17 is of such a character that this element, together with the hollow member 25 to which it is fixed, may be moved lengthwise of the tubular member 17 without any difiiculty and simply by overcoming the frictional contact between the locking element 22 and the tubular member 17. Further, this frictional contact is of such a character that the hollow member 25 is rotat able with respect to the locking element 22, the frictional contact between locking element 22 and tubular member 17 being suflicient to prevent rotating movement being imparted to the element 2-2 when the hollow member 25 is being rotated about the tubular member 17. Also, the frictional contact between the locking element 22 and tubular member 17 is of such as character that, when the hollow member 25 and element 22 are moved lengthwise of the tubular member 17 as a unit, these parts will remain in any position on the tubular member 17 to which they are moved.

As shown in FIG. 2, the inner tubular member 17 is formed with a collar 31 which is movable within the outer tubular member 16. When the tubular members 16 and 17 in FIG. 2 are moved apart, the shoulder 32 on the collar 31 moves against the lugs 21 which limit the extent to which the members 16 and 17 can be moved apart.

When the hollow member or nut 25 is not screwed tightly on the element 20, the tubular members 16 and 17 can be moved toward or from one another to adjust the wand 13 to whatever length is deemed most suitable for manipulating the nozzle 14 over a surface to be cleaned, such length being dependent either upon the height of the operator or other operating conditions present during a particular cleaning operation. Thereafter, the hollow member or nut 25 is screwed tightly on the element 20 to render locking member 22 effective to lock the tubular members 16 and 17 together.

The element 26 and hollow member 25 may be provided with left-hand threads whereby, when the hollow member 25 is rotated in the direction of the arrow A with respect to the threaded element 20, as shown in FIG. 2, the mem ber 25 and element 20 are drawn toward one another. As

rotating movement is being imparted to the hollow memher 25 to move the latter toward the left in FIG. 2, axial movement is imparted to the locking element 22 whereby the jaws 22a thereof are drawn against the inner surface of the conical-shaped section 18 of the outer tubular member 16. Since the locking element 22 is extremely resilient in character, due to the slots 23 and 23a which overlap one another in a lengthwise direction of the locking element, the conical-shaped section of the outer tube 16 acts to force the jaws 22a radially inward against the outer wall surface of inner tube 17 so as to grip the latter and hold fast thereto. Stated another way, the tightening of the hollow nut 25 on the externally threaded element 20 causes the beveled jaws 22a to become wedged between the inner surface of the conical-shaped section 18 of the outer tubular member 16 and the outer surface of the inner tubular member 17 to lock these tubular members to one another and prevent axial and rotative movement therebetween.

To loosen the locking device 15, the hollow nut 25 is rotated in the opposite direction from the direction of the arrow A in FIG. 2. It is'not necessary to unscrew the hollow nut 25 completely from the threaded element 20, but simply to move these parts axially from one another a sufficient distance so that the jaws 22a are no longer wedged between the conical-shaped section 18 of the outer tubular member 16 and outer surface of the inner tubular member 17. When this occurs, the tubular members 16 and 17 may be moved lengthwise with respect 28 and hollow member tightly together and subsequently manually loosen these parts without any difficulty and without the use of tools.

Although I have shown and described a single embodiment of my improved coupling device for locking telescopically fitted parts, I do not desire my invention to be limited to the particular arrangement set forth, and I intend in the succeeding claim to cover all modifications which do not depart from the spirit and scope of my invention.

What I claim is:

Inner and outer telescopically fitting hollow tubular members which are axially movable with respect to one another to provide a passage of variable length, the outer member at an extreme end thereof having an outwardly flared portion whose inner surface is spaced from the outer surface of the inner member to provide an annular gap therebetween, a split resilient ring snugly embracing the outer member which is externally threaded and suf ficiently resilient to be positioned on the outer member over its outwardly flared portion, means for removably holding the split resilient ring on the outer member at a region axially removed from the outwardly flared portion thereof, a collar disposed about the inner member which is rotatable and axially movable thereon, the collar being internally threaded at one end for threaded engagement with the split resilient ring and having an inturned flange at its other end, a deformable resilient hollow sleeve defining a truncated cone which, when undeformed, is of less internal diameter at its small or nose end than at its opposite larger end, the resilient sleeve being disposed about the inner member with its nose end in frictional engagement therewith and nearer to the gap than its opposite larger end, and the sleeve being disposed within the collar and having at its larger end an external circumferential groove which, when the resilient sleeve is undeformed, receives the flange for rotatably mounting the collar on the sleeve, the resilient sleeve being sufliciently deformable of the sleeve against the outer surface of the inner memrelieved and the inner and outer members are axially nylon has a relatively small co-eficientof friction and possesses such physical characteristics that, when it is employed to provide a part like the locking element 22 in the preferred embodiment illustrated and described above,

the resiliency of the part contributesto the effectiveness of the coupling or locking device. Further, plastic of a type like nylon inherently possesses an inherent lubricating quality which makes it possible to draw the elements movable with respect to one another.

References Cited in the file of this patent UNITED STATES PATENTS 260,966 Frey July 11, 1882 980,848 Stewart Jan. 3, 1911 1,078,129 Corrigan Nov. 11, 1913 1,266,989 Prime May 21, 1918 2,862,686 ,De Lano Nov. 14, 1944 2,527,988 Dillon Oct. 31, 1950 2,531,922 Seamark Nov. 28, 1950 2,647,798 Ballard Aug. 4, 1953 2,696,995 Schacht Dec; 14,1954 2,735,699 Chadbourne Feb. 21, 1956 2,839,316 Kasper June 17,1958

FOREIGN PATENTS 723,967 Germany Aug. 14, 1942 1953 694,268 v Great Britain July 15, 

